For security, remember it's a deterrent more then anything, since there are so many loopholes in the system. Let you feel safe, and think that it's serious business, but as we see time and again, it's far from that.
I needed some items, I gave them a quick check before checking them in at Heathrow, wasn't particularly concerned. Airmail to the Philippines isn't an option... Although even on arrival CEB, it appears that quite a few bags had been pilfered between landing and reaching the conveyor.